Paula's Choice Resist Barrier Repair Advanced Moisturizer

DESCRIPTION

What It Does: Delivers targeted skin-conditioning or bioactive benefits through a specific mechanism of action suited to the formulation's intended purpose.

Why It's Used: Specialty actives address specific skin concerns through targeted molecular mechanisms, providing efficacy beyond what base formulation ingredients alone can achieve.

How It Works: The bioactive compound interacts with specific molecular targets in skin cells or the extracellular matrix — enzymes, receptors, structural proteins, or signaling molecules — triggering beneficial biological responses.

Typically Found In: Serums,treatments,moisturizers,specialty products

TECHNICAL DETAILS

Primary Category: Specialty actives

Secondary Functions: Skin-conditioning,anti-aging

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.01–5%

SOURCING & ETHICS

Vegan Status: Yes

Halal Status: Yes

Source Notes: Specialty active ingredient; check individual sourcing for vegan status.

SKIN COMPATIBILITY

Irritancy Rating: 1

Comedogenicity Rating: 0

Sensitivity Concerns: Low sensitization potential at recommended use concentrations.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Well-characterized cosmetic ingredient with established safety profile. generally non-irritating at typical use concentrations. suitable for leave-on and rinse-off cosmetics.

Works Well With: Niacinamide,hyaluronic acid,vitamin c,peptides

Avoid Combining With: Incompatible with oxidizing agents; check ph stability

SCIENTIFIC NOTE

Specialty actives typically work through enzyme inhibition (e.g., tyrosinase inhibition for brightening, mmp inhibition for anti-aging), receptor activation (e.g., retinoid receptors, ppar-γ for barrier genes), or transcription factor modulation (e.g., nrf2 for antioxidant gene upregulation). structure-activity relationships determine potency and selectivity.

Last Verified: Cosing eu database; pcpc cosmetic ingredient safety reviews; ingredient-specific safety and efficacy literature

Primary Sources: 2025-01-15

DESCRIPTION

What It Does: Reduces fine lines, stimulates collagen, firms skin, and reduces inflammation.

Why It's Used: Fda-recognized anti-wrinkle active with multi-action collagen stimulation + wrinkle reduction + anti-inflammatory efficacy.

How It Works: Activates adenosine a2a receptors on fibroblasts stimulating collagen type i. also activates pka pathway promoting atp production and reducing inflammatory cytokines.

Typically Found In: Anti-aging serums,wrinkle treatments,korean skincare

TECHNICAL DETAILS

Primary Category: Active ingredient – purine nucleoside / anti-aging

Secondary Functions: Collagen stimulation,anti-inflammatory,cell energy

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.04%–0.1%

SOURCING & ETHICS

Vegan Status: Yes – synthetically produced

Halal Status: Yes

Source Notes: Synthetically produced for cosmetic use.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; excellent tolerability.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. fda-recognized as safe and effective anti-wrinkle ingredient. ewg score: 1.

Works Well With: Other b vitamins,niacinamide,antioxidant complexes

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

A 2002 clinical study demonstrated 0.04% adenosine cream significantly reduced wrinkle depth and increased skin elasticity after 4 weeks. fda recognition requires controlled clinical trial evidence.

Last Verified: Cosing database,adenosine anti-aging clinical data,fda otc anti-wrinkle monograph

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides essential barrier sterol function as one of three critical stratum corneum lipid components.

Why It's Used: Essential component of complete barrier repair formulations – the stratum corneum barrier requires ceramides:cholesterol:fatty acids in approximately 1:1:1 molar ratio for complete barrier restoration.

How It Works: Integrates between ceramide headgroups in lamellar body structures, providing fluidity and flexibility to the otherwise rigid ceramide-dominated lipid matrix. controls lamellar body phase behavior for functional barrier.

Typically Found In: Barrier repair moisturizers,eczema treatments,dry skin formulations

TECHNICAL DETAILS

Primary Category: Active ingredient – barrier sterol

Secondary Functions: Lamellar body structure,barrier sterol

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.01%–1%

SOURCING & ETHICS

Vegan Status: Conditional – animal-derived (lanolin) or plant-derived phytosterol analogs; verify

Halal Status: Conditional – verify source

Source Notes: Traditionally from lanolin (wool grease). plant-derived cholesterol alternatives include phytosterols, though these show slightly different barrier integration. verify for vegan/halal.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Endogenous molecule; excellent tolerability.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Exceptional safety profile. natural skin component. ewg score: 1.

Works Well With: Other ceramides,cholesterol,free fatty acids,hyaluronic acid,niacinamide

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Elias demonstrated that barrier repair requires all three lipid classes (ceramides, cholesterol, fatty acids) in approximately equimolar ratios. formulations providing only ceramides without cholesterol and fatty acids show significantly inferior barrier restoration vs complete triple-lipid combinations.

Last Verified: Cosing database,elias et al. barrier lipid ratio study,loden barrier repair review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Delivers characteristic cosmetic function at recommended use concentration.

Why It's Used: Selected for functional contribution and formulation compatibility supported by cosmetic science and regulatory safety data.

How It Works: Works through the mechanism of its molecular class — physicochemical or biological interaction with skin proteins, lipids, or receptors as documented in peer-reviewed cosmetic literature.

Typically Found In: Skin care formulations

TECHNICAL DETAILS

Primary Category: Active ingredient – cosmetic active

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–10%

SOURCING & ETHICS

Vegan Status: Conditional

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Cocoglycerides has an established safety and efficacy profile within the cosmetic regulatory framework at standard use concentrations.

Last Verified: Cosing database,cocoglycerides technical literature

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides antimicrobial skin conditioning with deodorant activity and preservation system enhancement.

Why It's Used: Multifunctional clean beauty preservation active — ethylhexylglycerin provides antimicrobial, deodorant, and skin conditioning in a single ingredient accepted in most natural cosmetic certification schemes.

How It Works: Glycerol ether provides antimicrobial via bacterial membrane phospholipid disruption. deodorant activity via reduction of underarm lipase enzyme activity (similar mechanism to triethyl citrate). skin conditioning from glycerol humectant component. synergistic with phenoxyethanol and diols.

Typically Found In: Natural preservation systems,deodorants,skin conditioning products

TECHNICAL DETAILS

Primary Category: Functional ingredient – antimicrobial glycerol ether

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–0.5%

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Ethylhexylglycerin's deodorant mechanism is pharmacologically identical to triethyl citrate: both inhibit skin surface microbial lipase enzymes that convert odourless triglycerides to odorous free fatty acids. the glycerol ether structure of ethylhexylglycerin, combined with the 2-ethylhexyl chain, provides lipase inhibition similar to ester-based lipase inhibitors from a different chemical class.

Last Verified: Cosing database,schülke sensiva sc 10 technical data,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Glycerin pulls water from the environment and deeper skin layers into the outer skin layer (epidermis), boosting moisture levels and keeping skin soft, smooth, and plump.

Why It's Used: It is used in virtually every moisturizer, serum, and cleanser because it is highly effective at hydrating skin, is well-tolerated by all skin types, and enhances the texture and spreadability of formulations.

How It Works: As a humectant, glycerin forms hydrogen bonds with water molecules, trapping them in the skin. it also reinforces the skin barrier by integrating into lipid structures between skin cells.

Typically Found In: Moisturizers,serums,cleansers,toners,sheet masks,sunscreens,body lotions,shampoos,conditioners

TECHNICAL DETAILS

Primary Category: Humectant

Secondary Functions: Skin barrier support,emollient,solvent

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–30% (typical: 3–10%)

SOURCING & ETHICS

Vegan Status: Yes – plant-derived (coconut, soy, palm) or synthetic

Halal Status: Yes – when plant-derived or synthetic; verify source with supplier

Source Notes: Derived from plant oils via hydrolysis or saponification; synthetic versions also available. palm-derived glycerin carries sustainability concerns.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low; non-irritating at all standard concentrations

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Extremely rare allergic reactions; generally safe for all skin types including sensitive and baby skin

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Widely recognized as safe. ewg hazard score: 1. no significant concerns for irritation, sensitization, or toxicity at typical concentrations (up to 50%).

Works Well With: Hyaluronic acid,ceramides,niacinamide,panthenol,urea,peptides,retinol,ahas/bhas

Avoid Combining With: No known incompatibilities at standard concentrations

SCIENTIFIC NOTE

Glycerin is an endogenous skin component found naturally in the stratum corneum. aquaporin-3 channels in keratinocytes facilitate glycerin transport, making it integral to natural skin hydration pathways.

Last Verified: Cosing database,cir safety assessment,ewg skin deep,inci decoder

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides antioxidant and preservative-boosting activity in a naturally-occurring clean-label phenolic.

Why It's Used: Clean-label preservation support — hydroxyacetophenone provides antioxidant and antimicrobial-boosting properties from a naturally-occurring compound accepted in natural cosmetic certifications.

How It Works: Para-hydroxyl group provides antioxidant radical scavenging. disrupts bacterial cell membrane penetration for preservative system boosting. anti-inflammatory via nf-kb inhibition. occurs naturally in plants including pear and raspberry as a secondary metabolite.

Typically Found In: Natural preservation systems,antioxidant serums,clean beauty

TECHNICAL DETAILS

Primary Category: Functional ingredient – antioxidant preservative booster

Secondary Functions: Free radical scavenging,anti-aging

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–1%

SOURCING & ETHICS

Vegan Status: Yes – natural from plants or synthetic

Halal Status: Yes

Source Notes: Plant-derived extract or synthetic.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; well-tolerated.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. ewg score: 1.

Works Well With: Vitamin c,vitamin e,ferulic acid,spf,other antioxidants

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Hydroxyacetophenone's natural occurrence in fruits (pear, raspberry, passion fruit) at detectable concentrations provides clean-label justification for use in natural cosmetics. its cosmos certification acceptance reflects the growing demand for functional preservation ingredients that meet natural certification criteria — an ingredient with genuine plant-origin credentials that provides meaningful antimicrobial and antioxidant functions simultaneously.

Last Verified: Cosing database,cosmos-standard approved ingredients,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Prevents microbial contamination and spoilage in cosmetic formulations.

Why It's Used: The benchmark cosmetic preservative – eu-permitted up to 1%, effective against virtually all cosmetically relevant microorganisms, and excellent tolerability.

How It Works: Phenol ring provides broad antimicrobial activity via disruption of bacterial and fungal cell membranes and inhibition of enzymatic activity. effective against gram-positive and gram-negative bacteria, yeasts (candida), and molds (aspergillus). activity ph range: 3-9.

Typically Found In: All cosmetic formulations as primary preservative

TECHNICAL DETAILS

Primary Category: Functional ingredient – broad-spectrum preservative

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–1% (eu max 1%)

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Eu cosmetics regulation max 1%. sccs assessed as safe at ≤1%. avoid use around eyes in baby products per some country regulations. ewg score: 4.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Phenoxyethanol's widespread adoption as the primary cosmetic preservative followed the phaseout of parabens from many formulations in the 2000s-2010s. despite having a comparable or better safety profile to parabens, it is often cited in 'free-from' formulations – a consumer perception issue rather than a scientific safety concern.

Last Verified: Cosing database,sccs opinion on phenoxyethanol,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Deposits a conditioning film on hair and skin through electrostatic attraction to negative cuticle/corneocyte surfaces, reduces hair-on-hair friction for improved combability and detangling, eliminates static charge buildup, and provides anti-frizz humidity resistance.

Why It's Used: Cationic polymers are the primary hair conditioning technology — the permanent positive quaternary ammonium groups provide substantive deposition that resists rinsing, delivering persistent conditioning between washes unlike small-molecule cationic conditioners.

How It Works: At shampoo/conditioner ph 4.5–5.5, hair cuticle carries net negative charge (isoelectric point ph ~3.5). polyquaternium cations undergo electrostatic attraction depositing on the cuticle surface. during rinsing, the deposited polymer film persists from reduced surface-solution equilibrium at low bulk concentration — substantive deposition from favourable interfacial versus bulk partitioning.

Typically Found In: Shampoos,conditioners,leave-in products

TECHNICAL DETAILS

Primary Category: Active ingredient – cosmetic active

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–3%

SOURCING & ETHICS

Vegan Status: Yes

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Different polyquaternium numbers indicate different backbone chemistries: pq-7 (acrylamide/quaternary acrylate copolymer) for leave-on flexibility; pq-10 (hydroxyethylcellulose/quaternary ammonium) for substantive deposition; pq-11 (vp/dimethylaminoethyl methacrylate) for styling fixation.

Last Verified: Cosing database,polyquaternium-51 cationic conditioning deposition review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides endogenous-skin-identical emolliency with exceptional stability and skin compatibility.

Why It's Used: The most skin-compatible emollient – chemically identical to human sebum squalene component with outstanding tolerability across all skin types.

How It Works: Fully saturated hydrocarbon with zero oxidation sites provides exceptional stability unlike squalene's 6 double bonds. integrates into stratum corneum lipid bilayers with near-perfect biocompatibility. provides antioxidant protection to formulation via radical quenching.

Typically Found In: Facial oils,serums,non-comedogenic moisturizers,luxury body care

TECHNICAL DETAILS

Primary Category: Functional ingredient – emollient

Secondary Functions: Maximum biocompatibility,antioxidant stabilizer,non-comedogenic

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–100%

SOURCING & ETHICS

Vegan Status: Conditional – plant-derived (sugarcane, olive) preferred; shark liver-derived being phased out

Halal Status: Yes – plant-derived

Source Notes: Sustainable plant-derived squalane from sugarcane fermentation (amyris) or olive oil fractionation is preferred over shark liver-derived. chemically identical regardless of source.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. ewg score: 1.

Works Well With: Humectants,ceramides,actives as carrier

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Squalene constitutes approximately 12-15% of human sebum – the highest proportion of any skin lipid. topical squalane (stable, hydrogenated form) replenishes this abundant endogenous skin lipid. the complete absence of oxidizable double bonds (unlike squalene's 6 double bonds) eliminates the pro-oxidant concerns of natural squalene oxidation.

Last Verified: Cosing database,huang et al. squalane review,cir safety assessment

Primary Sources: 2026-03-12